The Non-Langerhans Cell Histiocytoses (Rare Histiocytoses) - Clinical Aspects and Therapeutic Approaches.

Rare histiocytoses, also called non-Langerhans cell histiocytoses, include all proliferative disorders of histiocytes, macrophages and dendritic cells that are not classified as Langerhans cell histiocytosis (LCH) and do not belong to the hemophagocytic lymphohistiocytosis (HLH) group of diseases. Thus, the term includes numerous benign or malignant, localized or systemic, adult or pediatric diseases. The classification of the histiocytic disorders has been revised several times. Here, we follow the classification recently published by Jean Francois Emile and an international expert panel, defining subgroups of histiocytoses described as L-Group, C-Group, M-Group, R-Group, and H-Group, which stands for LCH-like, cutaneous or mucocutaneous, malignant, Rosai-Dorfman-Disease like and HLH like. Some of the diseases have an excellent prognosis after resection or even disappear spontanously, others progress rapidly, requiring intensive systemic therapies. The malignant non-Langerhans cell histiocytoses in general have a poor prognosis, here, complex chemotherapy protocols are usually applied, with inconsistant results. An interesting perspective in non-malignant rare histiocytoses might be small molecular inhibitors, in particular BRAF inhibitors, since BRAF mutations have been found in some subtypes of non-Langerhans cell histiocytoses. By prospective and retrospective collection of experiences in a new registry (the "International Rare Histiocytic Disorders Registry", IRHDR), knowledge about these rare diseases might hopefully be improved.

Micafungin twice weekly as antifungal prophylaxis in paediatric patients at high risk for invasive fungal disease.

BACKGROUND: Current guidelines recommend antifungal prophylaxis for children at high risk for invasive fungal disease (IFD), but the use of polyenes and triazoles may not be feasible in some patients due to toxicities and drug-drug interactions. Micafungin is well tolerated, with intravenous daily dosing being the current standard. Recent reports indicate safety and efficacy of intermittent dosing of micafungin. METHODS: We analysed safety, efficacy and micafungin serum concentrations of children at high risk for IFD receiving prophylactic micafungin between 3 and 4 mg/kg twice weekly. All children were intolerant or had contraindications to polyenes and triazoles. RESULTS: A total of 21 children (median age = 9 years) at high risk for IFD were included in the analysis. No significant clinical adverse event occurred, and end of treatment values of parameters of renal and hepatic function in serum were not different from baseline. Proven or probable breakthrough IFD did not occur in any of the patients. In 9 out of 11 patients in whom plasma micafungin concentrations were assessed, the first trough concentration exceeded 150 ng/mL, a concentration proposed to be effective for prophylaxis. CONCLUSIONS: Our data indicate that micafungin administered twice weekly at a dosage of 3-4 mg/kg of bodyweight could be a convenient, safe and efficient alternative for antifungal prophylaxis in children at high risk for IFD.

Identification of invasive fungal diseases in immunocompromised patients by combining an Aspergillus specific PCR with a multifungal DNA-microarray from primary clinical samples.

The increasing incidence of invasive fungal diseases (IFD), most of all invasive aspergillosis (IA) in immunocompromised patients emphasises the need to improve the diagnostic tools for detection of fungal pathogens. We investigated the diagnostic performance of a multifungal DNA-microarray detecting 15 different fungi [Aspergillus, Candida, Fusarium, Mucor, Rhizopus, Scedosporium and Trichosporon species (spp.)] in addition to an Aspergillus specific polymerase chain reaction (PCR) assay. Biopsies, bronchoalveolar lavage and peripheral blood samples of 133 immunocompromised patients (pts) were investigated by a multifungal DNA-microarray as well as a nested Aspergillus specific PCR assay. Patients had proven (n = 18), probable (n = 29), possible (n = 48) and no IFD (n = 38) and were mostly under antifungal therapy at the time of sampling. The results were compared to culture, histopathology, imaging and serology, respectively. For the non-Aspergillus IFD the microarray analysis yielded in all samples a sensitivity of 64% and a specificity of 80%. Best results for the detection of all IFD were achieved by combining DNA-microarray and Aspergillus specific PCR in biopsy samples (sensitivity 79%; specificity 71%). The molecular assays in combination identify genomic DNA of fungal pathogens and may improve identification of causative pathogens of IFD and help overcoming the diagnostic uncertainty of culture and/or histopathology findings, even during antifungal therapy.

Randomised Introduction of 2-CDA as Intensification during Consolidation for Children with High-risk AML--results from Study AML-BFM 2004.

BACKGROUND: The outcome in children and adolescents with high-risk (HR) acute myeloid leukemia (AML) is still unsatisfactory. Therefore, in study AML-BFM 2004 we aimed to improve outcome of HR-patients by adding moderately dosed 2-Chloro-2-Deoxyadenosine (2-CDA) to the respective consolidation treatment backbone without increasing toxicity. The aim was to improve prognosis especially in FAB M4/M5/MLL patients, who represent the largest subgroup of HR patients. PATIENTS AND METHODS: In total, 343 children and adolescents with HR-AML were randomized to receive or not 2-CDA (6 mg/m²/d, days 1, 3) in combination with cytarabine/idarubicine (AI=500 mg/m² cytarabine 5 days continuous infusion plus 7 mg/m²/d idarubicin, days 3 and 5). RESULTS: RESULTS for patients of the AI/2-CDA arm (n=168) vs. the AI-arm (n=175) were similar: 5-year overall survival 68±4 vs. 72±4%, plogrank=0.38, event-free survival 53±4 vs. 49±4%, plogrank=0.77; cumulative incidence of relapse at 5 years: 35±4 vs. 37±4%, p(Gray)=0.89. RESULTS in patients with MLL rearrangement or FAB M4/M5 were also similar in the treatment groups. In addition, toxicities did not differ between the two arms. CONCLUSION: We conclude that additional, moderate dose 2-CDA does not improve prognosis in HR-patients when given during consolidation treatment. Its effect might be too low in this multidrug regimen, where the strongest effects are achieved during induction, or the chosen dose of 2-CDA might have been too low.

Aspergillus PCR-based investigation of fresh tissue and effusion samples in patients with suspected invasive Aspergillosis enhances diagnostic capabilities.

Although it is a severe complication in immunocompromised patients, diagnosing invasive fungal disease (IFD), especially invasive aspergillosis (IA), remains difficult. In certain clinical scenarios, examining tissue samples for identification of the infectious organism becomes important. As culture-based methods rarely yield results, the performance of an Aspergillus-specific nested PCR in fresh tissue or pleural effusion samples was evaluated. Fresh tissue (n = 59) and effusion (n = 47) specimens from 79 immunocompromised patients were subjected to an Aspergillus-specific PCR assay. Twenty-six patients had proven (n = 20) or probable (n = 6) IFD, according to the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) criteria, while the remaining patients were classified as having either possible IFD (n = 30) or no IFD (n = 23). IA was identified as the underlying IFD in 21/26 proven/probable cases. PCR positivity was observed for 18/21 proven/probable and 6 possible IA cases; cases classified as no IA did not show positive signals. Patients with proven IFD (n = 5) with cultures positive for non-Aspergillus molds also had negative Aspergillus PCR results. Aspergillus PCR performance analysis yielded sensitivity and specificity values of 86% (95% confidence interval [CI], 65% to 95%) and 100% (95% CI, 86% to 100%), respectively, thus leading to a diagnostic odds ratio of >200. In this analysis, good diagnostic performance of the PCR assay for detection of IA was observed for tissue samples, while effusion samples showed lower sensitivity rates. PCR testing represents a complementary tool; a positive PCR result strengthens the likelihood of IA, whereas IA seems unlikely in cases with negative results but findings could indicate non-Aspergillus IFD. Thus, PCR testing of these specimens enhances the diagnostic capabilities.

No effect of antifungal compounds on functional properties of human antifungal T-helper type 1 cells.

Despite the availability of new antifungal compounds, invasive fungal disease is associated with a high mortality in hematopoietic stem cell transplant (HSCT) recipients. A growing body of evidence suggests that T lymphocytes from the T-helper type 1 (TH 1) play an important role in the antifungal host defense, and preliminary data indicate a potential benefit of infusing donor-derived antifungal TH 1 cells to HSCT patients suffering from invasive fungal disease. Unfortunately, it is unclear to date whether the function of these cells is affected by concomitantly administered antifungal agents. We therefore analyzed the effects of various concentrations of commonly used antifungal compounds such as amphotericin B, caspofungin, fluconazole, voriconazole, and posaconazole on the functional properties of cultivated human antifungal TH 1 cells. None of the antifungal compounds tested significantly influenced the secretion of interferon-γ and tumor necrosis factor-α, and only posaconazole at high concentrations slightly decreased proliferation of antifungal TH 1 cells. Our data indicate that the antifungal agents tested do not significantly affect the functional properties of antifungal TH 1 cells and can therefore be concomitantly administered.

Mould-active compared with fluconazole prophylaxis to prevent invasive fungal diseases in cancer patients receiving chemotherapy or haematopoietic stem-cell transplantation: a systematic review and meta-analysis of randomised controlled trials.

BACKGROUND: Objectives were to compare systemic mould-active vs fluconazole prophylaxis in cancer patients receiving chemotherapy or haematopoietic stem cell transplantation (HSCT). METHODS: We searched OVID MEDLINE and the Cochrane Central Register of Controlled Trials (1948-August 2011) and EMBASE (1980-August 2011). Randomised controlled trials of mould-active vs fluconazole prophylaxis in cancer or HSCT patients were included. Primary outcome was proven/probable invasive fungal infections (IFI). Analysis was completed by computing relative risks (RRs) using a random-effects model and Mantel-Haenszel method. RESULTS: From 984 reviewed articles, 20 were included in this review. Mould-active compared with fluconazole prophylaxis significantly reduced the number of proven/probable IFI (RR 0.71, 95% CI 0.52 to 0.98; P=0.03). Mould-active prophylaxis also decreased the risk of invasive aspergillosis (IA; RR 0.53, 95% confidence interval (CI) 0.37-0.75; P=0.0004) and IFI-related mortality (RR 0.67, 95% CI 0.47-0.96; P=0.03) but is also associated with an increased risk of adverse events (AEs) leading to antifungal discontinuation (RR 1.95, 95% CI 1.24-3.07; P=0.004). There was no decrease in overall mortality (RR 1.0; 95% CI 0.88-1.13; P=0.96). CONCLUSION: Mould-active compared with fluconazole prophylaxis significantly reduces proven/probable IFI, IA, and IFI-related mortality in cancer patients receiving chemotherapy or HSCT, but increases AE and does not affect overall mortality. (PROSPERO Registration: CRD420111174).

Use of linezolid in neonatal and pediatric inpatient facilities--results of a retrospective multicenter survey.

The purpose of this investigation was to describe the use of linezolid in pediatric inpatient facilities. A retrospective multicenter survey including data from nine participating tertiary care pediatric inpatient facilities in Germany and Austria was undertaken. Data on 126 off-label linezolid treatment courses administered to 108 patients were documented. The survey comprises linezolid treatment in a broad spectrum of clinical indications to children of all age groups; the median age was 6.8 years (interquartile range 0.6-15.5 years; range 0.1-21.2 years; ten patients were older than 18 years of age but were treated in pediatric inpatient units). Of the 126 treatment courses, 27 (21%) were administered to preterm infants, 64 (51%) to pediatric oncology patients, and 5% to patients soon after liver transplantation. In 25%, the infection was related to a medical device. Linezolid iv treatment was started after intensive pre-treatment (up to 11 other antibiotics for a median duration of 14 days) and changed to enteral administration in only 4% of all iv courses. In 39 (53%) of 74 courses administered to children older than 1 week and younger than 12 years of age, the dose was not adjusted to age-related pharmacokinetic parameters. In only 17 courses (13%) was a pediatric infectious disease consultant involved in the clinical decision algorithm. Linezolid seemed to have contributed to a favorable outcome in 70% of all treatment courses in this survey. Although retrospective, this survey generates interesting data on the off-label use of linezolid and highlights several important clinical aspects in which the use of this rescue antibiotic in children might be improved.

Outpatient and oral antibiotic management of low-risk febrile neutropenia are effective in children--a systematic review of prospective trials.

BACKGROUND: There is no consensus on whether therapeutic intensity can be reduced safely in children with low-risk febrile neutropenia (FN). Our primary objective was to determine whether there is a difference in efficacy between outpatient and inpatient management of children with low-risk FN. Our secondary objective was to compare oral and parenteral antibiotic therapy in this population. METHODS: We performed electronic searches of Ovid Medline, EMBASE, and the Cochrane Central Register of Controlled Trials, and limited studies to prospective pediatric trials in low-risk FN. Percentages were used as the effect measure. RESULTS: From 7,281 reviewed articles, 16 were included in the meta-analysis. Treatment failure, including antibiotic modification, was less likely to occur in the outpatient setting compared with the inpatient setting (15 % versus 28 %, P = 0.04) but was not significantly different between oral and parenteral antibiotic regimens (20 % versus 22 %, P = 0.68). Of the 953 episodes treated in the outpatient setting and 676 episodes treated with oral antibiotics, none were associated with infection-related mortality. CONCLUSION: Based on the combination of results from all prospective studies to date, outpatient and oral antibiotic management of low-risk FN are effective in children and should be incorporated into clinical care where feasible.

Impact of minimal residual disease detection prior to autologous stem cell transplantation for post-transplant outcome in high risk neuroblastoma.

Autologous stem cell transplantation (SCT) has become standard therapy in high risk stage IV neuroblastoma (NB) patients. Residual NB cells in the bone marrow (BM) shortly before SCT may shape the overall survival.Thus, we sought to thoroughly investigate minimal residual disease (MRD) in BM prior to SCT using conventional and real time RT-PCR for tyrosine hydroxylase (TH) as well as morphology. To avoid influence of residual NB cells in the stem cell harvest, 17 patients transplanted with MRD negative grafts (n=11 CD34-selected and n=6 unmanipulated) are included in the final analysis, only.35% of these patients are alive with a median follow up of 8.6 years. In the BM of 9/17 patients residual NB cells could be detected < 40 d before SCT. These patients had a significant lower overall survival compared to patients without BM involvement based on combined RT-PCR and morphology results (11% vs. 62%, p=0.026) or using RT-PCR, only (p=0.01). In contrast morphology on its own did not lead to a significant discrimination between both groups.Our results obtained in a small cohort of stage IV NB patients suggest that MRD diagnostic in the BM shortly before SCT might be a valuable predictive tool for these patients but requires conformation in a multicenter study.

Evaluation of the prognostic meaning of C-reactive protein (CRP) in children and adolescents with classical Hodgkin's lymphoma (HL).

BACKGROUND: In adult cancer patients the negative predictive value of elevated CRP levels has been described for several malignancies. Only few studies have analyzed the prognostic role of CRP in children and adolescents with classical HL. In these studies elevated CRP levels correlate with the presence of classical risk factors and adverse outcome. PATIENTS AND METHODS: The prognostic role of CRP for patients with classical HL admitted to the GPOH-HD-2002 study was analyzed retrospectively. RESULTS: CRP levels were documented for 369 of 573 patients. Significant (p<0.05) increased median CRP levels were found in the presence of B-Symptoms (25.7 vs. 5.1 mg/l), extranodal involvement (21.5 vs. 7.5 mg/l), elevated erythrocyte sedimentation rate (ESR, 13.0 vs. 1.0 mg/l) and stage III/IV disease (15.5 vs. 5.3 mg/l). 83.9% of patients with elevated and 45.8% of patients with normal CRP had an ESR >30 mm/h. CONCLUSION: Elevated CRP levels were associated with classical risk factors of HL. CRP and ESR may reflect different biological processes. CRP was prognostic within early stage TG-1 patients treated with reduced treatment, but not within advanced stage TG-2+3.

[Interdisciplinary AWMF guideline for the treatment of primary antibody deficiencies]. / Interdisziplinäre AWMF-Leitlinie zur Therapie primärer Antikörpermangelerkrankungen.

BACKGROUND: Currently, management of antibody deficient patients differs significantly among caregivers. Evidence and consensus based (S3) guidelines for the treatment of primary antibody deficiencies were developed to improve the management of these patients. METHODS: Based on a thorough analysis of current evidence (systematic literature search in PubMed; deadline November 2011) 14 recommendations were finalized during a consensus meeting in Frankfurt in November 2011 using structured consensus methods (nominal group technique). Experts were nominated by their scientific societies/patient initiatives (Tab. 1). RESULTS: The guidelines focus on indication, practical issues and monitoring of immunoglobulin replacement therapy as well as on different routes of administration. Furthermore recommendations regarding supportive measures such as antiinfective therapy, vaccinations and physiotherapy are given. Combining literature evidence and experience of caregivers within this evidence and consensus based guidelines offers the chance to improve the quality of care for anti-body deficient patients.

Phase II dose escalation study of caspofungin for invasive Aspergillosis.

Our objective was to evaluate the maximum tolerated dose of caspofungin for invasive aspergillosis (IA). The safety and pharmacokinetics of escalating dosages of caspofungin were investigated in IA. Eight patients each received caspofungin 70, 100, 150, or 200 mg once a day (QD). Dose-limiting toxicity (DLT) was defined as the same non-hematological treatment-related adverse event of grade ≥ 4 in 2 of 8 patients or ≥ 3 in 4 of 8 patients in a cohort. A total of 46 patients (median age, 61 years; 21 female; 89% with hematological malignancies) received caspofungin (9, 8, 9, and 20 patients in the 70-, 100-, 150-, and 200-mg cohorts) for a median of 24.5 days. Plasma pharmacokinetics were linear across the investigated dosages and followed a two-compartment model, with weight as the covariate on clearance and sex as the covariate on central volume of distribution. Simulated peak plasma concentrations at steady state ranged from 14.2 to 40.6 mg/liter (28%), trough concentrations from 4.1 to 11.8 mg/liter (58%), and area under the concentration-time curve from 175 to 500 mg/liter/h (32%) (geometric mean, geometric coefficient of variation). Treatment was well tolerated without dose-limiting toxicity. The rate of complete or partial responses was 54.3%, and the overall mortality at 12-week follow-up was 28.3%. In first-line treatment of invasive aspergillosis, daily doses of up to 200 mg caspofungin were well tolerated and the maximum tolerated dose was not reached. Pharmacokinetics was linear. Response rates were similar to those previously reported for voriconazole and liposomal amphotericin.

[Febrile neutropenia in pediatric and adolescent cancer patients]. / Fieber während der Granulozytopenie bei krebskranken Kindern und Jugendlichen.

Febrile neutropenia is the most common potential emergency situation in children and adolescents with cancer. The host response of these patients is severely compromised by treatment-induced immunosuppression resulting in a lack of important defence mechanisms, so that bacterial infections and in certain risk groups also fungal infections can be life threatening. As the clinical course of these infectious complications may be rapid and fatal, early antibiotic treatment can save lives. This article aims to raise awareness to this emergency situation and gives an overview of the management of pediatric cancer patients with febrile neutropenia.

Posaconazole salvage treatment in paediatric patients: a multicentre survey.

While a paediatric dosage has not been defined, posaconazole is occasionally being used in children. We conducted a multicentre retrospective survey and identified 15 patients (median age 10 years [range 3.6-17.5]) who received posaconazole salvage therapy for proven (9 patients) or probable (6 patients) invasive fungal infections. Posaconazole was administered for a median of 32 days (range 4-262) at a median dosage of 21 mg/kg (range 4.8-33.3). None of the patients discontinued therapy due to adverse events, which were mostly mild and observed in 11 patients. Complete or partial responses were observed in 4/7 patients with zygomycosis, 3/4 patients with invasive mould infection, 1/2 patients with invasive aspergillosis and 1/2 patients with chronic disseminated candidiasis. We conclude from the data that posaconazole displays favourable safety and tolerance and may be useful for management of individual paediatric patients with invasive infections.

ESCMID-ECMM guideline: diagnosis and management of invasive aspergillosis in neonates and children.

SCOPE: Presenting symptoms, distributions and patterns of diseases and vulnerability to invasive aspergillosis (IA) are similar between children and adults. However, differences exist in the epidemiology and underlying conditions, the usefulness of newer diagnostic tools, the pharmacology of antifungal agents and in the evidence from interventional phase 3 clinical trials. Therefore, the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and the European Confederation of Medical Mycology (ECMM) have developed a paediatric-specific guideline for the diagnosis and management of IA in neonates and children. METHODS: Review and discussion of the scientific literature and grading of the available quality of evidence was performed by the paediatric subgroup of the ESCMID-ECMM-European Respiratory Society (ERS) Aspergillus disease guideline working group, which was assigned the mandate for the development of neonatal- and paediatric-specific recommendations. QUESTIONS: Questions addressed by the guideline included the epidemiology of IA in neonates and children; which paediatric patients may benefit from antifungal prophylaxis; how to diagnose IA in neonates and children; which antifungal agents are available for use in neonates and children; which antifungal agents are suitable for prophylaxis and treatment of IA in neonates and children; what is the role of therapeutic drug monitoring of azole antifungals; and which management strategies are suitable to be used in paediatric patients. This guideline provides recommendations for the diagnosis, prevention and treatment of IA in the paediatric population, including neonates. The aim of this guideline is to facilitate optimal management of neonates and children at risk for or diagnosed with IA.

Voxel-based morphometry and diffusion-tensor MR imaging of the brain in long-term survivors of childhood leukemia.

The aims of this study were to detect morphological changes in neuroanatomical components in adult survivors of acute lymphoblastic leukemia (ALL). Voxel-based morphometry (VBM) can be used to detect subtle structural changes in brain morphology and via analysis of fractional anisotropy (FA), diffusion-tensor imaging (DTI) can non-invasively probe white matter (WM) integrity. We used VBM and DTI to examine 20 long-term survivors of ALL and 21 healthy matched controls. Ten ALL survivors received chemotherapy and irradiation; ten survivors received chemotherapy alone during childhood. Imaging was performed on a 3.0-T MRI. For VBM, group comparisons of segmented T1-weighted grey matter (GM) and WM images from controls and ALL survivors were performed separately for patients who received chemotherapy alone and who received chemotherapy and irradiation. For DTI, FA in WM was compared for the same groups. Survivors of childhood ALL who underwent cranial irradiation during childhood had smaller WM volumes and reduced GM concentration within the caudate nucleus and thalamus. The FA in WM was reduced in adult survivors of ALL but the effect was more severe after combined treatment with irradiation and chemotherapy. Our results indicate that DTI and VBM can reveal persistent long-term WM and caudate changes in children after ALL treatment, even without T2 changes in conventional imaging.

Diagnosis and management of Aspergillus diseases: executive summary of the 2017 ESCMID-ECMM-ERS guideline.

The European Society for Clinical Microbiology and Infectious Diseases, the European Confederation of Medical Mycology and the European Respiratory Society Joint Clinical Guidelines focus on diagnosis and management of aspergillosis. Of the numerous recommendations, a few are summarized here. Chest computed tomography as well as bronchoscopy with bronchoalveolar lavage (BAL) in patients with suspicion of pulmonary invasive aspergillosis (IA) are strongly recommended. For diagnosis, direct microscopy, preferably using optical brighteners, histopathology and culture are strongly recommended. Serum and BAL galactomannan measures are recommended as markers for the diagnosis of IA. PCR should be considered in conjunction with other diagnostic tests. Pathogen identification to species complex level is strongly recommended for all clinically relevant Aspergillus isolates; antifungal susceptibility testing should be performed in patients with invasive disease in regions with resistance found in contemporary surveillance programmes. Isavuconazole and voriconazole are the preferred agents for first-line treatment of pulmonary IA, whereas liposomal amphotericin B is moderately supported. Combinations of antifungals as primary treatment options are not recommended. Therapeutic drug monitoring is strongly recommended for patients receiving posaconazole suspension or any form of voriconazole for IA treatment, and in refractory disease, where a personalized approach considering reversal of predisposing factors, switching drug class and surgical intervention is also strongly recommended. Primary prophylaxis with posaconazole is strongly recommended in patients with acute myelogenous leukaemia or myelodysplastic syndrome receiving induction chemotherapy. Secondary prophylaxis is strongly recommended in high-risk patients. We strongly recommend treatment duration based on clinical improvement, degree of immunosuppression and response on imaging.

Host defense molecule polymorphisms influence the risk for immune-mediated complications in chronic granulomatous disease.

Chronic granulomatous disease (CGD) is an inherited disorder of phagocyte function in which defective superoxide production results in deficient microbicidal activity. CGD patients suffer from recurrent, life-threatening infections, and nearly half develop chronic gastrointestinal (GI) complications (colitis, gastric outlet obstruction, or perirectal abscess) and/or autoimmune/rheumatologic disorders (AIDs). To identify genetic modifiers of disease severity, we studied a cohort of 129 CGD patients, in whom seven candidate genes (myeloperoxidase [MPO], mannose binding lectin [MBL], Fcgamma receptors IIa, IIIa, IIIb, TNF-alpha, and IL-1 receptor antagonist), each containing a physiologically relevant polymorphism predicted to influence the host inflammatory response, were selected for analysis. Genotypes of MPO (P = 0.003) and FcgammaRIIIb (P = 0.007) were strongly associated with an increased risk for GI complications, while an FcgammaRIIa (P = 0.05) genotype was suggestive for an association. Patients with all three associated genotypes had the highest risk for GI complications (P < 0.0001). The risk of AIDs was strongly associated with variant alleles of MBL (P = 0.01) and weakly associated with an FcgammaRIIa genotype (P = 0.04). Patients with variant forms of both MBL and FcgammaRIIa had the highest risk of developing an AID (P = 0.003).

Immune recovery in children undergoing allogeneic stem cell transplantation: absolute CD8+ CD3+ count reconstitution is associated with survival.

To evaluate the correlation between kinetics of immune reconstitution and survival, we prospectively evaluated lymphocyte subsets in 32 paediatric patients undergoing allogeneic stem cell transplantation (SCT) for haematological malignancies. Four-colour flow cytometric analysis was performed at short intervals with a median follow-up of 4 years post SCT. A total of 50% of patients reached age-matched 5th percentile of natural killer, cytotoxic T, B and helper T cells 4, 9, 20 and 28 weeks after SCT, respectively, which increased to more than 80% within 1 year after SCT. Transplantation of peripheral blood stem cells (PBSC) seemed to elicit the fastest reconstitution of CD3+, CD4+ CD3+, CD8+ CD3+ and naïve T cells compared to bone marrow (BM) or CD34-selected PBSC, which did not differ. Most importantly, we observed a significantly higher number of survivors among patients whose CD8+ CD3+ absolute counts rose above the 5th percentile of age-matched normal levels during the first year post SCT compared to patients who never reached these levels (19/25 vs 0/7, P<0.001). This was still present in both subgroups, BM- and CD34-selected grafts (P=0.03, 0.02). These results from a small patient sample underline the importance of particular lymphocyte subsets for the outcome of children undergoing SCT. A larger study with detailed subset analysis is underway.